X9420_06 Datasheet, PDF (3/19 Pages) Intersil Corporation – Single Digitally Controlled Potentiometer

X9420
PIN DESCRIPTIONS
Host Interface Pins
Serial Output (SO)
SO is a push/pull serial data output pin. During a read
cycle, data is shifted out on this pin. Data is clocked
out by the falling edge of the serial clock.
Serial Input
SI is the serial data input pin. All opcodes, byte
addresses and data to be written to the potentiometer
and pot register are input on this pin. Data is latched
by the rising edge of the serial clock.
Serial Clock (SCK)
The SCK input is used to clock data into and out of the
X9420.
Chip Select (CS)
When CS is HIGH, the X9420 is deselected and the
SO pin is at high impedance, and (unless an internal
write cycle is underway) the device will be in the
standby state. CS LOW enables the X9420, placing it
in the active power mode. It should be noted that after
a power-up, a HIGH to LOW transition on CS is
required prior to the start of any operation.
Hold (HOLD)
HOLD is used in conjunction with the CS pin to select
the device. Once the part is selected and a serial
sequence is underway, HOLD may be used to pause
the serial communication with the controller without
resetting the serial sequence. To pause, HOLD must
be brought LOW while SCK is LOW. To resume
communication, HOLD is brought HIGH, again while
SCK is LOW. If the pause feature is not used, HOLD
should be held HIGH at all times.
Device Address (A₀)
The address inputs is used to set the least significant
bit of the 8-bit slave address. A match in the slave
address serial data stream must be made with the
address input in order to initiate communication with
the X9420. A maximum of 2 devices may occupy the
SPI serial bus.
Potentiometer Pins
V_H/R_H, V_L/R_L
The V_H/R_H and V_L/R_L input are equivalent to the
terminal connections on either end of a mechanical
potentiometer.
V_W/R_W
The wiper output is equivalent to the wiper output of a
mechanical potentiometer.
Hardware Write Protect Input (WP)
The WP pin when LOW prevents nonvolatile writes to
the Data Registers. Writing to the Wiper Counter
Register is not restricted.
Analog Supplies (V+, V-)
The analog supplies V+, V- are the supply voltages for
the XDCP analog section.
System/Digital Supply (V_CC)
V_CC is the supply voltage for the system/digital
section. V_SS is the system ground.
PIN CONFIGURATION
V_CC
CS
R_L/V_L
R_H/V_H
R_W/V_W
SI
WP
V_SS
DIP/SOIC
1
16
2
15
3
14
4
13
5 ^X9420 12
6
11
7
10
8
9
V+
NC
A0
SO
HOLD
SCK
NC
V-
CS
R_L/V_L
R_H/V_H
R_W/V_W
SI
WP
V_SS
TSSOP
1
14
2
13
3
12
4 X9420 11
5
10
6
9
7
8
V_CC
V+
A0
SO
HOLD
SCK
V-
3
FN8195.1
April 26, 2006